#ifndef __M_FMT_H__
#define __M_FMT_H__

#include "level.hpp"
#include "message.hpp"
#include <cassert>
#include <sstream>
#include <memory>
#include <ctime>
#include <vector>
namespace mylog
{
    // 抽象格式化子项基类
    class FormatItem
    {
    public:
        using ptr = std::shared_ptr<FormatItem>;
        virtual void format(std::ostream &out, const LogMsg &msg) = 0;
    };
    // 派生格式化子项子类 -- 消息，等级，时间，文件名，行号，线程id，日志器名，制表符，换行，其他
    class MsgFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, const LogMsg &msg) override
        {
            out << msg._payload;
        }
    };
    class LevelFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, const LogMsg &msg) override
        {
            out << LogLevel::toString(msg._level);
        }
    };
    class TimeFormatItem : public FormatItem
    {
    public:
        TimeFormatItem(const std::string &fmt = "%H:%M:%S") : _time_fmt(fmt) {}
        void format(std::ostream &out, const LogMsg &msg) override
        {
            struct tm t;
            localtime_r(&msg._ctime, &t);
            char tmp[32] = {0};
            strftime(tmp, 31, _time_fmt.c_str(), &t);
            out << tmp;
        }

    private:
        std::string _time_fmt; //%H:%M:%S
    };
    class FileFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, const LogMsg &msg) override
        {
            out << msg._file;
        }
    };
    class LineFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, const LogMsg &msg) override
        {
            out << msg._line;
        }
    };
    class ThreadFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, const LogMsg &msg) override
        {
            out << msg._tid;
        }
    };
    class LoggerFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, const LogMsg &msg) override
        {
            out << msg._logger;
        }
    };
    class TabFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, const LogMsg &msg) override
        {
            out << "\t";
        }
    };
    class NlineFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, const LogMsg &msg) override
        {
            out << "\n";
        }
    };
    // abcde[]{}等
    class OtherFormatItem : public FormatItem
    {
    public:
        OtherFormatItem(const std::string &str) : _str(str) {}
        void format(std::ostream &out, const LogMsg &msg) override
        {
            out << _str;
        }

    private:
        std::string _str;
    };

    /*
        %d代表日期包含子格式{%H:%M:%S}
        %t表示线程id
        %c表示日志器名称
        %f表示源码文件名
        %l表示源码行号
        %p表示日志级别
        %T表示日志缩进
        %m表示消息主体
        %n表示换行
    */
    class Formatter
    {
    public:
        using ptr = std::shared_ptr<Formatter>;    
        Formatter(const std::string &pattern = "[%d{%H:%M:%S}][%t][%c][%f:%l][%p]%T%m%n")
            : _pattern(pattern)
        {
            assert(parsePattern());
        }
        // 对msg进行格式化
        void format(std::ostream &out, const LogMsg &msg)
        {
            for (auto &item : _items)
            {
                item->format(out, msg);
            }
        }
        std::string format(const LogMsg &msg)
        {
            std::stringstream ss;
            format(ss, msg);
            return ss.str();
        }

    private:
        // 对格式化字符进行解析
        //[%d{%H:%M:%S}][%t][%c][%f:%l][%p]%T%m%n
        bool parsePattern()
        {
            // 1.对格式化规则字符串进行解析
            std::vector<std::pair<std::string, std::string>> fmt_order;
            size_t pos = 0;
            std::string key, val;
            while (pos < _pattern.size())
            {
                // 1.处理原始字符串--判断是否是%，不是就是原始字符

                if (_pattern[pos] != '%')
                {
                    val.push_back(_pattern[pos++]);
                    continue;
                }
                // 能走下来就代表pos位置就是%
                if (pos + 1 < _pattern.size() && _pattern[pos + 1] == '%')
                {
                    val.push_back('%');
                    pos += 2;
                    continue;
                }
                // 能走下来代表%后是格式化字符，代表原始字符串处理完毕
                if (!val.empty())
                {
                    fmt_order.push_back(std::make_pair("", val));
                    val.clear();
                }
                // 这时pos指向%位置，进行格式化处理
                pos += 1; // 这一步后指向格式化字符位置
                if (pos == _pattern.size())
                {
                    std::cout << "%后，没有对应格式化字符!\n";
                    return false;
                }
                key = _pattern[pos];
                // 这时pos指向格式化字符的位置;
                pos += 1;
                if (pos < _pattern.size() && _pattern[pos] == '{')
                {
                    pos += 1; // pos指向{之后，子规则的起始位置
                    while (pos < _pattern.size() && _pattern[pos] != '}')
                    {
                        val.push_back(_pattern[pos++]);
                    }
                    // 走到末尾跳出循环，则没有遇到}，代表格式错误
                    if (pos == _pattern.size())
                    {
                        std::cout << "子规则{}匹配错误！\n";
                        return false; // 没找到}
                    }
                    pos += 1; // 此时pos在}位置+1到新一轮位置
                }
                fmt_order.push_back(std::make_pair(key, val));
                key.clear();
                val.clear();
            }
            // 2.根据解析得到的数据初始化格式化子项数组的成员
            for (auto &it : fmt_order)
            {
                _items.push_back(createItem(it.first, it.second));
            }
            return true;
        }

        // 根据不同的格式化字符创建不同的格式化子项对象
        FormatItem::ptr createItem(const std::string &key, const std::string &val)
        {
            if (key == "d")
                return std::make_shared<TimeFormatItem>(val);
            if (key == "t")
                return std::make_shared<ThreadFormatItem>();
            if (key == "c")
                return std::make_shared<LoggerFormatItem>();
            if (key == "f")
                return std::make_shared<FileFormatItem>();
            if (key == "l")
                return std::make_shared<LineFormatItem>();
            if (key == "p")
                return std::make_shared<LevelFormatItem>();
            if (key == "T")
                return std::make_shared<TabFormatItem>();
            if (key == "m")
                return std::make_shared<MsgFormatItem>();
            if (key == "n")
                return std::make_shared<NlineFormatItem>();
            if (key == "")
                return std::make_shared<OtherFormatItem>(val);
            std::cout << "没有对应的格式化字符：%" << key << std::endl;
            abort();
            return FormatItem::ptr();
        }

    private:
        std::vector<FormatItem::ptr> _items;
        std::string _pattern; // 格式化规则字串
    }; // class Formatter

} // namespace mylog

#endif